The present invention relates to a self-powered fluid meter. More specifically, the present invention provides a method and device for generating electrical pulses from the kinetic energy of a moving fluid. These pulses may then be used to provide data for fluid measurement and to power components associated with such measurement. By way of example, the pulses may power circuitry or other electronics that perform various fluid measurements based on information provided by the pulses.
Conventional devices for fluid flow measurement are known. Measurements of the rate or volume of fluid flow may be desirable or even mandatory for operations involving the transport, manufacture, or storage of various fluids. While various devices and techniques for fluid measurement have been applied, many utilize a measuring element placed in the path of fluid flow. The measuring element is generally configured such that the kinetic energy of the moving fluid is translated so as to cause the measuring element to move in a way that is measurable. For example, the measuring element may be configured to rotate upon being placed into the path of a moving fluid. Various mechanisms may then be provided for detecting the rotational speed of the measuring element and, in some cases, to determine the total number of revolutions. Knowing the relationship between a revolution of measuring element and the corresponding volume of fluid that is displaced or passed through the meter, the volume and/or rate of fluid flow may be calculated or determined.
Where conventional electronics or other circuitry are provided for performing various functions related to the fluid measurement, power must be provided to operate the same. In some applications, an independent power source may be readily available for supply to the fluid meter. However, in other applications, an independent power source may be unavailable, impractical, or less economical to supply. Batteries offer only a limited solution due to their typical limitations such as battery life, costs, and reliability in harsh environments. Thus, a fluid meter capable of performing fluid measurements while also providing the power necessary for those measurements is desirable.
The present invention provides a method and device for fluid measurement that is self-powered. More specifically, the present invention provides for generating electrical pulses from the kinetic energy of a moving fluid while measuring such fluid. The pulses provide data for fluid measurements and power for components associated with taking, storing, or reporting of such measurements.
The present invention provides numerous embodiments for a self-powered fluid meter. A summary of exemplary embodiments will now be provided. However, using the teachings disclosed herein, other examples will be apparent to those of ordinary skill in the art and such are within the spirit and scope of the present invention.
In one exemplary embodiment, the present invention provides for a self-powered fluid meter by creating a rotating magnetic field from the kinetic energy of a fluid moving through the fluid meter. Electrical pulses are then created using a magnetic flux sensor positioned within the influence of the rotating magnetic field. These electrical pulses are then used to power a circuit.
Numerous examples exist for creating a rotating magnetic field from the kinetic energy of a moving fluid. By way of example only, a turbine or nutating disk may be placed into the path of a moving fluid so as to translate the kinetic energy of the moving fluid into a rotating shaft. Such rotating shaft may be connected to a magnet or configured so as to cause a magnet to rotate. Alternatively, numerous magnets may be configured so as to present alternating fields of magnetic flux when caused to rotate through connection with the shaft.
A magnetic flux sensor is then positioned within the influence of the magnetic field created by the magnet or magnets. As this field rotates, the magnetic flux sensor is subjected to alternating flux polarity. In response, the magnetic flux sensor creates electrical pulses. Any sensor capable of creating an electrical pulse upon being subjected to a magnetic field of changing flux polarity may be used. By way of example only, one such type of sensor that may be used to create electrical pulses upon being subjected to changes in magnetic flux polarity is disclosed in U.S. Pat. No. 3,820,090, issued to Wiegand, which is incorporated in its entirety herein by reference. This reference discloses a magnetic sensor that may be formed by cold working a wire constructed from iron, cobalt, and vanadium. When placed in the presence of a changing magnetic field, the wire will produce an electrical pulse that may be detected and harnessed by appropriate circuitry. Alternatively, when placed in the presence of a changing magnetic field, the wire will also induce a voltage across a coil located near the wire. This resulting electrical pulse may also be detected or harnessed by appropriate circuitry.
The electrical pulses generated by the magnetic flux sensor may be used to power a circuit performing functions related to fluid measurement. By way of example only, such a circuit may include a counter or totalizer that determines the volume of fluid or rate of fluid moving through the fluid meter by counting the number of electrical pulses. The circuit may also include a memory function, powered by the pulses, for storing information related to the fluid measurement such as the total volume or rate of fluid flow. The information may be stored in the form of code to maximize data retention and endurance. The use of a memory circuit may be advantageous for applications where retrieval of measurement data may be intermittent. Consider, for example, residential water meters that are checked on a periodic basis for billing of customers.
By way of further example, the electrical pulses may also power a circuit that performs a function of transmitting information related to the fluid measurement. More specifically, the circuit may be configured for determining the volume and/or rate of fluid flow, storing that information, and then transmitting that information at a later time. In the example of residential water meters, the water meter may be configured with circuitry that is powered by the electrical pulses, that determines the total volume of water consumed during a particular period, stores such information, and then transmits that information by radio signals on a periodic basis for billing purposes. Numerous other circuits and applications will be apparent to one of ordinary skill in the art using the teachings disclosed herein.
In another exemplary embodiment of the present invention, a self-powered device for measuring fluid flow includes a meter housing that defines a fluid inlet and a fluid outlet. A meter magnet is configured within the meter housing such that fluid flowing into the meter housing through the fluid inlet and exiting through the fluid outlet causes the meter magnet to rotate. The meter magnet may be of various configurations. For example, the meter magnet may be disk shaped with dual or multiple poles. By way of further example, the meter magnet may actually consist of multiple magnets configured within the housing so as to be rotatable.
A register housing is provided that is attached to the meter housing. A register magnet is located within the register housing and is configured to be in magnetic communication with the meter magnet. This configuration is structured so that as the meter magnet is caused to rotate, the register magnet also rotates. As with the meter magnet, the register magnet may consist of a single magnet with dual or multiple poles. Alternatively, the register magnet may include a number of magnets configured so as to create fields of alternating magnetic flux polarity upon rotation.
A generating element is positioned within the field of magnetic flux created by the register magnet. This generating element is configured for creating electrical pulses upon being subjected to the fields of changing magnetic flux created by the rotation of the register magnet. Any generating element capable of creating electrical pulses upon being subjected to fields of changing magnetic flux may be used. By way of example, a Wiegand wire may be used as discussed above.
The register housing may be configured with various circuits for performing functions related to fluid measurement as discussed above. The electrical pulses provided by the generating element are used to both power this circuitry as well as provide information related to the fluid measurement. By providing for a register housing that is detachable, the functions performed by the circuitry configured within the register housing may be modified or customized by simply substituting a new register housing with the desired circuitry.
In another exemplary embodiment of the present invention, a device for fluid measurement is provided that includes a chamber configured with an inlet and an outlet for fluid flow. At least one magnet is located in the chamber. The magnet may be disk or cylindrically shaped and include dual or multiple poles so as to provide fields of alternating magnetic flux polarity upon the rotation of the magnet. Alternatively, several magnets may be configured within the chamber and oriented so as to provide fields of changing magnetic flux polarity upon rotation. For example, two or more magnets may be positioned on a disk or other wheel at equally spaced intervals. The orientation of the magnets, with respect to north and south, are then alternated so as to provide a field of alternating magnetic flux polarity during rotation.
A measuring element is also located within the chamber. The measuring element is in mechanical communication with the magnet and is so configured such that a fluid flowing into the chamber through the fluid inlet acts upon the measuring element so as to cause the magnet or magnets to rotate. By way of example, the measuring element may be connected to the magnet by a shaft.
Within the field of alternating magnetic flux polarity created by the rotation of the magnet or magnets discussed above, a generating element is positioned. The generating element is configured so as to create electric pulses upon being subjected to the changing field of magnetic flux created by the rotation of the magnet or magnets. By way of example only, a Wiegand wire, as discussed above, may be used as an operating element.
The electrical pulses created by the generating element may be used to provide both information related to fluid measurement and power for circuitry performing functions necessary to such fluid measurement. By way of example, circuitry may be provided for determining the amount of fluid flowing through the meter, storing such information, and/or transmitting such information.
In still another exemplary embodiment of the present invention, a self-powered fluid measuring device may include a chamber with at least one magnet located within said chamber. As discussed above, the magnet may be constructed from a variety of shapes with single or multiple poles. Furthermore, multiple magnets may be utilized to create a field of alternating magnet flux polarity. A measuring element is configured in mechanical communication with the magnet. The measuring element is configured such that upon being placed into the path of a flowing fluid the measuring element causes the magnet to rotate within the chamber.
For this embodiment of the present invention, the measuring element is not required to be located within the chamber that contains the magnet. This embodiment may be useful, for example, where the measuring element is inserted into a pipe or other conduit for the fluid being measured. The measuring element may take on a variety of shapes and structures for converting the kinetic energy of the flowing fluid into the rotations of the magnet. For example, the measuring element may consist of a turbine, nutating disk, or rotor connected to the magnet by a rotatable shaft.
A generating element is positioned within the influence of the magnetic flux of the rotating magnet or magnets. Upon being subjected to fields of alternating flux polarity, the generating element creates a series of electrical pulses. As with the other embodiments described above, these pulses may be used to carry both information and provide power for circuitry related to the fluid measurement.
These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and independent claims. The accompanying drawings, which are incorporated herein and constitute a part of this specification, illustrate an embodiment of the present invention and together with the description, serve to explain the principals and objectives of the invention.